1. Technical Field
The invention relates generally to electronic devices having photographic functions, and more particularly to an electronic device with a portable optical module.
2. Description of Related Art
Currently, digital camera modules are in widespread use in a variety of portable electronic devices. Most portable electronic devices are becoming progressively more miniaturized over time, and digital camera modules are correspondingly becoming smaller and smaller. For example, digital camera modules are now widely available as a feature of a mobile phone, notebook and personal digital assistant (PDA). Nevertheless, in spite of the small size of a contemporary digital camera module, consumers still demand excellent imaging. The quality of the image provided is mainly dependent upon the optical elements of the digital camera modules.
A digital camera module typically includes a lens module, a barrel and an image sensor, etc. The image sensor uses a charge-coupled device (CCD), a complementary metal oxide semiconductor (CMOS) or the like to process a high quality image such as a VGA format (640×480 pixels) in a small area (3.6×2.7 mm). The image sensor can convert a light incident thereon into analog electrical signals that can be further converted into digital form. The lens module is formed over the image sensor for focusing the incident light onto the corresponding image sensor. Furthermore an additional optical module, such as a filter, can be attached to the lens module to improve exposure and specific color filtering.
In recent years, miniaturization of electronic devices has continued apace. Digital camera modules are often mounted on these small portable electronic devices, thus making miniaturization of the camera modules used with electronic devices necessary. The conventional way to attach an additional optical module, such as a filter, to the digital camera module is by screwing the optical module onto the digital camera module onto a screw thread thereof. However, since the digital camera module is small, it is difficult for users to screw the additional optical module onto the digital camera module. In addition, digital camera module barrels are usually made of plastic and frequent screwing and unscrewing may cause damage to the plastic barrel.
What is needed, therefore, is an electronic device with a portable optical module. The portable optical module should be easy to attach to and detach from the digital camera module of an electronic device such as a mobile phone, a notebook or a personal digital assistant.